Sewing machine



FIG. 1 is a top plan view of an embodiment of a sewing machine showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and

FIG. 7 is a front perspective view thereof. 

The ornamental design for a sewing machine, as shown. 